Back Maqnit anomaliyası Azerbaijani Магнитна аномалия Bulgarian Magnetische Anomalie German Anomalía magnética Spanish بیهنجاری مغناطیسی Persian Anomalie magnétique French Magnetska anomalija Croatian Մագնիսական անոմալիա Armenian Segultruflanir Icelandic Anomalia magnetica Italian
In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material. The magnetic variation (geomagnetic reversals) in successive bands of ocean floor parallel with mid-ocean ridges was important evidence for seafloor spreading, a concept central to the theory of plate tectonics.